Hydraulic piston pump for the pumping of viscous pulpy or plastic substances



P 1964 F. w. SCHWING 3146'721 HYDRAULIC PISTON PUMP FOR THE PUMPING OF VISCOUS PULPY OR PLASTIC SUBSTANCES Filed July 27, 1961 7 Sheets-Sheet 1 INVENTOR. FRIEDRICH W. SCHWING BY WMQQM ATTORNEY Sept. 1, 1964 HYDRAULIC Filed July 27. 1961 F W. SCHWING PISTON I UMP FOR THE PUMPING OF VISCOUS PULPY OR PLASTIC SUBSTANCES 7 Sheets-Sheet 2 Fig. 2

INVENTOR. FRIEDRICH W. SCHWING WWW/2% ATTORNEY Sept. 1, 1964 HYDRAULIC PISTON I UMP FOR THE PUMPING OF VISCOUS PULPY OR PLASTIC SUBSTANCES Filed July 27, 1961 F W. SCHWING 7 Sheets-Sheet 3 l-D N V a a 1n 1:: R1 F f A. Q a w J N in N o N m --a l=d- N L] I? :nr 1 l.-

('0 i N N D N N 8 J a g INVENTOR.

9/ FRIEDRICH w. SCHWING @MML ATTORNEY P 64 F. w. SCHWING 3,146,721

HYDRAULIC PISTON PUMP FOR THE PUMPING OF VISCCUS PULPY OR PLASTIC SUBSTANCES Filed July 27. 1961 7 Sheets-Sheet 4 INVENTOR. FRIEDRICH W. SCHWING BY WM ZZM ATTORNEY Sept. 1, 1964 w c w 3,146,721

HYDRAULIC PISTON PUMP FOR THE PUMPING OF VISCOUS PULPY 0R PLASTIC SUBSTANCES Filed July 2'7, 1951 7 Sheets-Sheet 5 INVENTOR. FRIEDRICH W. SCHWING BY @MMLM ATTORNEY p 1964 F. w. SCHWING 3,146,721

HYDRAULIC PISTON PUMP FOR THE PUMPING OF VISCOUS PULPY OR PLASTIC SUBSTANCES Filed July 27, 1951 7 Sheets-Sheet 6 INVENTOR. FRIEDRICH W. SCHWING ATTORNEY Sept. 1, 1964 HYDRAULIC PISTON PUMP FOR THE PUMPING OF VISCOUS Filed July 27, 1951 F. w. SCHWING 3,146,721

PULPY OR PLASTIC SUBSTANCES 7 Sheets-Sheet 7 INVENTOR. FRIEDRICH w. SCHWING WM A).

ATTORNEY United States Patent 3,146,721 HYDRAULIC PISTON PUMP FOR THE PUMPING 9F VISCOUS PULPY 0R PLASTIC SUBSTANCES Friedrich Wiihelrn Schwing, Dorstener Strasse 424,

Wanne Eiekel, Germany Filed July 27, 1961, Ser. No. 127,335

Claims priority, application Germany Aug. 8, 1960 8 Claims. (Cl. 10349) For the pumping of viscous, pulpy or plastic substances and particularly concrete, frequently short stroke piston pumps are used which are driven through crankshafts or racks and also such with pistons moving in counter-stroke.

As the piston diameter has a favorable ratio to the diameter of the pumping conduit, it is necessary, in order to attain an economic pumping output, to chose a relatively high stroke sequence. The slide valves, moving according to the suction and pressure strokes and frequently in the form of rotating valves, are actuated corresponding to the stroke frequency.

Through the mechanical action and control of the particular movements the pump and pipeline are subject to strong stresses by shock which have to be absorbed in corresponding, mostly costly, foundations. The great wear caused by the high stroke frequency and the danger of breakage of certain elements in the mechanism of the pump due to the appearance of sizeable forces, leads to frequent unpleasant interruptions in the pumping operatron.

In order to reduce the stroke frequency, designs of pumps have become known, in which the length of the stroke has been increased. The drive of the pump pistons is effected through piston rods in the shape of geared racks. A drive pinion set in rotating motion between these racks, moves one piston in pressure stroke and the other piston in suction stroke.

Furthermore, a type of pump has become known amongst others, in which the disadvantages of mechanical action are said to be avoided by hydraulic operation. In a pump a loose piston is propelled by water pressure. The return stroke of the piston is effected by suction of the water. The remainders of the substance to be pumped, such as sand and cement, contaminate the Water. With increased duration of operation these impurities produce wear of the pressure producing element and endanger the reliability of operation. In case the friction between cylinder and piston becomes greater than the available suction, the piston comes to a stop and the pumping action is interrupted. Such failures can only be corrected by time consuming and expensive work. The frequently long and circuitous pipeline has to be emptied and cleaned as the pumping substance hardens during interruptions and cannot be set in motion again.

With pumps of this kind only half the working time is utilized for the pressure stroke, while the other half is necessary for the suction stroke. The pumping substance in the pipeline comes to rest after each pressure stroke and must again and again be accelerated anew. The nonuniform power consumption has highly unfavorable effect on the pressure generator necessary for the operation. Moreover, the drive equipment is functioning uneconomically as full output is only absorbed during half the working cycle, while the motor output has to be chosen for the highest occurring load.

The purpose of the present invention is the creation of a failure-proof device for the pumping of vicous, pulpy or plastic substances, for instance concrete, while avoiding the tendency to trouble and the deficiencies of devices known to this date.

This is achieved by hydraulic motion of the pumping piston through a piston rod, with the device being constructed suitably for the object in view as a twin cylinder pump, so that alternately one piston is effecting the pressure stroke and the other the suction stroke. By the way of example, the associated slide valves are controlled, constrained to the corresponding stroke, in such a manner that, at the instant of operation of the slide valve, the pump piston is at rest so that all internal stresses in the pumping substance are relieved and the slide valve can easily separate said pumping substance. By changing slide valve positions an alternative connection is created be tween the pumping substance hopper and the pumping tube in which the pump piston starts its suction stroke, while the umping tube in which the pressure stroke is about to begin is connected to the delivery pipe.

While the front side of the pump piston sucks in and forces out the pumping substance, the reverse side of the piston moves rinsing water at zero pressure, by way of an equalizer and a low lying settling tank, in which the heavy impurities of the rinsing water due to eventual remainders of the pumping substance are deposited, without said rinsing water coming into contact with the hydrauilc installation proper.

Various examples of possible realizations of the object of the invention are presented in simplified form in the accompanying drawings in which FIGURE 1 is a schematic illustration of a pump assembly embodying the novel features of the invention wherein the pump pistons are disposed to work away from each other;

FIGURE 2 is a schematic illustration of a pump assembly embodying the novel features of the structure illustrated in FIGURE 1 except that the pump pistons are arranged to work toward each other;

FIGURE 3 is a schematic illustration of a pump assembly embodying the novel features of the structures illustrated in FIGURES l and 2 except that the pump pistons are arranged to work parallel to each other;

FIGURE 4 is a schematic elevational view of the assembly illustrated in FIGURE 3;

FIGURE 5 is an elevational view of a mobile pumping assembly embodying the novel concepts of the invention;

FIGURE 6 is a top view of a portion of the apparatus illustrated in FIGURE 5;

FIGURE 7 is a sectional view taken along line AB of FIGURE 6;

FIGURE 8 is a sectional view of one of the pumps illustrated in FIGURE 6;

FlGURE 9 is a partial sectional view of the pump assembiy illustrated in FIGURE 6 taken along line E-F of FIGURE 10;

FIGURE 10 is a partial sectional view of the pump assembly illustrated in FIGURE 6 taken along line G-H of FIGURE 9; and

FIGURE 11 is a partial sectional view of the apparatus illustrated in FIGURES 9 and 10 taken along line C-D of FIGURE 10.

FIGURE 1 shows a pump with two pump pistons 2 Working away from each other connected by a piston rod 1, with two rotary valves 3 and 3', which are actuated through a hydraulic work cylinder 4, where the control of the pistons 2 and the valves 3 and 3' is effected through a cam operated control valve 5. The pump cylinders 6 and 6' are filled with water behind the pump piston 2, said water being moved at zero pressure through pipelines 7 and '7, by way of an equalizing tank 8. Remainders of the pumping substance adhering eventually to the walls or" pump cylinder 6 and 6' are rinsed away and are carried by way of pipelines 9 and 9' into the settling tanks 10 and it).

As shown in FIGURE 1, the suction of the pumping substance from the hopper 11 through the rotary valve 3 and the pressure stroke through rotary valve 3 into the delivery line 12. are terminated.

FIGURE 2 shows the schematic drawing of a pump in which the pump pistons 13 and 13 are working toward each other and a rotary valve 15 is provided between the pumping tubes 14 and 14', while the controlling action takes place as described in FIGURE 1.

FIGURE 3 shows the schematic drawing of a pump whose pumping cylinders 15 and 16' are arranged parallel to each other and are equipped with hydraulically operated slide valves 1'7 and I7.

Pump piston 2 has terminated the suction stroke and pump piston 2 has terminated the pressure stroke. The piston rods 1 and 1' are fitted at their outer ends with cross members 18 and 18' which carry projecting parts 19 and I9 and are connected to the outer ends of the piston rods of the hydraulic work cylinder pair 26 and Ztl. In its end position projecting part 19' has through cam 21, reversed control valve 22 and has thus directed the flow of the pressure medium from the pres sure generator through line 23 into the hydraulic work cylinders 24 and 24, which in turn moves the slide valves 17 and 17' in such manner, that pump piston 2 can start the pressure stroke and pump piston 2 the suction stroke. This action is initiated when the work cylinder 24 through a bar linkage 25, on reaching its end position, switches valve 22' in such a manner, that the pressure medium is directed from the pressure generator through line 2-6 into work cylinder 2d of the pump cylinder 16'. Thereby pistons 27 are moved forward in work cylinders 20'.

As said pistons are connected through their piston rods 28' and the cross member 18 with the piston rod 1 of the pump piston 2', pump piston Z pushes the previously sucked in pumping substance into the delivery line 12'. The circulating medium, displaced by the pistons 27 is forced through connecting line 29 into hydraulic work cylinders 2t) against pistons 27, which, connected by piston rod 23 and the cross member 13 and piston rod 1 to pump piston 2, cause the suction stroke in pumping tube 16. The pressure medium displaced by pistons 2'7 is brought back into the supply tank of the pressure generator through line 26 and valve 22.

As soon as the projecting part 19 hits cam 21 of the control valve 22 the above described work sequence is repeated with changed sides. Thereby an automatic work method is made possible. For transportation of the pump it is possible to retract both piston rod systems by actuating valve 3%.

FIGURE 4 shows a pump, as shown in FIGURE 3, in side view. Especially recognizable herein is the pumping substance hopper 11 as also the rinsing equipment for the pumping cylinder 16, which have not been shown in FIGURE 3 for the sake of better clarity. The rinsing water equalizing tank 8 is connected through line '7 and the settling tank It through line 9 with the pumping cylinder 16. Furthermore, 11 represents the pumping substance hopper, 17 the slide valve for the suction side, 17 the slide valve toward the pressure line.

In place of control through projecting parts and/or camshafts, control of the work movements is also possible through electrical contacts or timing relays or of combinations thereof.

The base frame 31 is provided in FIGURE with a carriage axle and a folding support. On the inclined base frame two parallel work cylinders fill actuated by pressure oil or the like are flange-mounted to the water tank 8. The piston rods 1 of the hydraulic work cylinders 20 protrude through the tank 8, up into the pump cylinder 16 and carry at their front end movably mounted and safely afiixed to each, a pump piston 2. Both pump cylinders 16 are placed likewise parallel and coaxially opposite onto the water tank 8. With their other open end, the pump cylinders 16 are connected to the pumping substance hopper 11. Through the opposing Wall, the delivery pipe issues into the filling funnel 11 by way of a step-shaped end piece 32. This piece can rotate in a bearing sleeve 33 and is embraced at its lower end by a swinging lever 34 which is fixed to a pivot 35, seated in the container wall on the prolonged axis of the pumping tube. To the outer end of this pivot is attached a double swinging lever 35, at the ends of which hydraulic work cylinders 37 effect a swinging aside of the step-shaped pumping tube 32, on the inside of the pumping substance hopper I1, alternately in front of the pumping cylinders 16, and this according to the momentary suction or pressure stroke of the pistons 2 moving therein. In order to increase the mixing action already achieved through the radial swinging motion, the swivel mounted pumping tube is provided with mixing arms 38 and rigid or elastic scrapers 39.

The water tank 3 located between the hydraulic work cylinders 26 and the pumping cylinders 16 has a fresh water intake 49 and two used water outlets 41 and further two rapid closure cleaning apertures 42. In its lower part the water tank is divided by a separating wall 43. At the bottom of each of the two chambers thus formed is located an outlet valve 44 and a case 45 surrounding same.

It serves in this manner for the rinsing and lubrication of the pump cylinders 16. Remainders of the pumping substance which have eventually passed beyond pistons 2 thereby make their way into water tank 8. Through the used water outlets 41, it is possible to let out the turbid water or remove eventual sediments through the cleaning apertures 42. In case the filled pump line 32 has to be emptied after termination of the pumping operation, a closure plate 46 with two inlet valves 47 through it, is brought into position on a ledge formed as intrinsic part with the separating wall and the outside wall. Two water pressure chambers are thus formed, through which pistons 2 of the pump cylinders 16 are, alternatingly, sucking fresh water through the valves 47 from the fresh water supply tank formed above the closure plate 46, and forcing it through the bottom valves 4-4 into a pipeline starting thereunder. The pumpline 32' had been previously separated close to the pumping substance hopper 11 and connected with line 48. The piston rods 1 are mushroom shaped at their front end. Thereby pistons 2 can be installed or removed easily but first of all, adapt themselves always very well to the cylinder walls. Through a reserve stroke provided in the hydraulic work cylinders 29, it is possible to withdraw the pistons 2 up into the water tank 8, which are freely accessible from above, examine them and if necessary quickly change them.

The hydraulic energy for the pump comes from a separate motor driven adjustable pressure generator. However, the latter can also be placed on the base frame 31. The pipeline for the pressure oil stream leads to the control elements which are placed in the enclosure 49. From there the pressure oil goes, for example through automatically acting reversing valves, and this depending on a preset hydraulic pressure, to the hydraulic work cylinders 20 and 37.

The pressure is adjusted according to the normal resistance of the actually used pipeline length. In case the resistance surpasses the preset pressure, for instance due to a momentary blocking in the pumping line or similar causes, the work cycle is immediately automatically reversed, the increased pressure decreased by the following suction stroke and the blocking relieved. Then, the resistance again having become normal, permits the pump to continue operation with its full stroke.

The pumping substance hopper 11 is provided with inlets 59, in the space covered by the agitator for the introduction of liquid or powdery additions for the correction of already filled pumping substances.

What I claim is:

1. A pump for placing plastic concrete comprising:

a vertically extending hopper for containing plastic cement;

first and second parallel spaced apart pump cylinders,

the bottom of said hopper opening into each of said cylinders near the outlet ends thereof;

valve means for selectively closing the openings between said hopper and said pump cylinders;

a discharge pipe connected to the outlet ends of said pump cylinders;

gate valve means for selectively closing the outlet ends of said pump cylinders;

a piston reciprocatively mounted in each of said pump cylinders;

a piston rod connected to each of said pistons and extending outwardly through the ends of said pump cylinders opposite the outlet ends thereof;

a pair of hydraulic cylinders mounted in parallel spaced relation adjacent each of said first and said second pump cylinders, each of said hydraulic cylinders having a piston and a piston rod assembly reciprocatively mounted therein;

means for coupling the outer ends of the piston rods of each of said pairs of hydraulic cylinders together, said means further being connected to the respective one of said piston rods of said first and said second pump cylinder;

cleaning liquid inlet means providing communication between a cleaning liquid reservoir and the interior of said pump cylinders through the rearwardly disposed end portion of said pump cylinder for admitting the cleaning liquid thereto;

cleaning liquid outlet means providing communication between the interior of said pump cylinders and a settling tank through the rearwardly disposed end portions of said pump cylinders;

pressure fluid inlet and outlet means for each of said hydraulic cylinders for effecting reciprocating movement of respective areas of said piston and piston rod assemblies to thereby simultaneously effect movement of said piston and piston rod mounted in the respective pump cylinder;

and means for synchronizing the movements of said valve means, said gate valve means, and the piston and piston rod assemblies of said hydraulic cylinders so that as the piston and piston rod assembly connected to the piston of said first pump cylinder is caused to move forwardly toward the outlet end thereof the piston of said second pump cylinder is caused to move rearwardly, simultaneously said valve means has closed the opening between said hopper and said first pump cylinder and has opened the opening between said hopper and said second pump cylinder, and said gate valve means has opened the outlet end of said first pump cylinder and has closed the outlet end of said second pump cylinder.

2. A pump for placing plastic concrete comprising:

a vertically extending hopper for containing plastic concrete;

a first pump cylinder and a reciprocatively slidable piston therein;

a second pump cylinder and a reciprocatively slidable piston therein;

each pump cylinder having one end opening into the interior of said hopper;

a discharge pipe having one end communicating with the interior of said hopper;

a delivery pipe having one end rotatably coupled to the one end of said discharge pipe, the other end of said delivery pipe being selectively connectable with the one end of said first and said second pump cylinders;

pressure fluid drive means connected to the slidable pistons in said first and said second pump cylinders;

pressure fluid control means operable to supply pressure fluid to said drive means to actuate the slidable pistons to effect alternate reciprocal movement thereof in the respective ones of said pump cylinders; and

means for rotating the one end of said delivery pipe to selectively connect the other end of said delivery pipe to the one end of said first and second pump cylinders, said means being synchronized with said pressure control means to effect communication between said discharge pipe and said pump cylinders through said delivery pipe during the movement of the respective piston in a direction toward the end thereof opening into the interior of said hopper.

3. The invention defined in claim 2 wherein the other end of each of said pump cylinders communicates with a source of cleaning liquid, said liquid is introduced into said cylinder during the movement of the respective piston toward the one end thereof and is ejected therefrom during the opposite movement of the piston.

4. The invention defined in claim 2 wherein agitating means are aflixed to said delivery pipe and extend into the interior portion of said hopper for agitating the concrete contained therein when the other end of said delivery pipe is caused to be moved from one position to another.

5. The invention defined in claim 2 wherein said hopper is provided with an opening for cleaning the interior thereof.

6. The invention defined in claim 4 wherein said agitating means are finger-like elements having sufficiently sharp leading edge portions to cut through coarse pieces of the plastic concrete.

7. The invention defined in claim 2 wherein the pistons are flexibly affixed to said drive means.

8. The invention defined in claim 1 wherein said means for synchronizing includes cam elements which are energized by said piston rods upon reaching their outermost position.

References Cited in the file of this patent UNITED STATES PATENTS 2,485,208 Longenecker Oct. 18, 1949 2,570,835 Mooney et a1. Oct. 9, 1951 2,690,715 Pope Oct. 5, 1954 2,752,075 Hill June 26, 1956 2,797,645 Kastner July 2, 1957 2,998,781 Triebel Sept. 5, 1961 FOREIGN PATENTS 698,629 Great Britain Oct. 21, 1953 

1. A PUMP FOR PLACING PLASTIC CONCRETE COMPRISING: A VERTICALLY EXTENDING HOPPER FOR CONTAINING PLASTIC CEMENT; FIRST AND SECOND PARALLEL SPACED APART PUMP CYLINDERS, THE BOTTOM OF SAID HOPPER OPENING INTO EACH OF SAID CYLINDERS NEAR THE OUTLET ENDS THEREOF; VALVE MEANS FOR SELECTIVELY CLOSING THE OPENINGS BETWEEN SAID HOPPER AND SAID PUMP CYLINDERS; A DISCHARGE PIPE CONNECTED TO THE OUTLET ENDS OF SAID PUMP CYLINDERS; GATE VALVE MEANS FOR SELECTIVELY CLOSING THE OUTLET ENDS OF SAID PUMP CYLINDERS; A PISTON RECIPROCATIVELY MOUNTED IN EACH OF SAID PUMP CYLINDERS; A PISTON ROD CONNECTED TO EACH OF SAID PISTONS AND EXTENDING OUTWARDLY THROUGH THE ENDS OF SAID PUMP CYLINDERS OPPOSITE THE OUTLET ENDS THEREOF; A PAIR OF HYDRAULIC CYLINDERS MOUNTED IN PARALLEL SPACED RELATION ADJACENT EACH OF SAID FIRST AND SAID SECOND PUMP CYLINDERS, EACH OF SAID HYDRAULIC CYLINDERS HAVING A PISTON AND A PISTON ROD ASSEMBLY RECIPROCATIVELY MOUNTED THEREIN; MEANS FOR COUPLING THE OUTER ENDS OF THE PISTON RODS OF EACH OF SAID PAIRS OF HYDRAULIC CYLINDERS TOGETHER, SAID MEANS FURTHER BEING CONNECTED TO THE RESPECTIVE ONE OF SAID PISTON RODS OF SAID FIRST AND SAID SECOND PUMP CYLINDER; CLEANING LIQUID INLET MEANS PROVIDING COMMUNICATION BETWEEN A CLEANING LIQUID RESERVOIR AND THE INTERIOR OF SAID PUMP CYLINDERS THROUGH THE REARWARDLY DISPOSED END PORTION OF SAID PUMP CYLINDER FOR ADMITTING THE CLEANING LIQUID THERETO; CLEANING LIQUID OUTLET MEANS PROVIDING COMMUNICATION BETWEEN THE INTERIOR OF SAID PUMP CYLINDERS AND A SETTLING TANK THROUGH THE REARWARDLY DISPOSED END PORTIONS OF SAID PUMP CYLINDERS; PRESSURE FLUID INLET AND OUTLET MEANS FOR EACH OF SAID HYDRAULIC CYLINDERS FOR EFFECTING RECIPROCATING MOVEMENT OF RESPECTIVE AREAS OF SAID PISTON AND PISTON ROD ASSEMBLIES TO THEREBY SIMULTANEOUSLY EFFECT MOVEMENT OF SAID PISTON AND PISTON ROD MOUNTED IN THE RESPECTIVE PUMP CYLINDER; AND MEANS FOR SYNCHRONIZING THE MOVEMENTS OF SAID VALVE MEANS, SAID GATE VALVE MEANS, AND THE PISTON AND PISTON ROD ASSEMBLIES OF SAID HYDRAULIC CYLINDERS SO THAT AS THE PISTON AND PISTON ROD ASSEMBLY CONNECTED TO THE PISTON OF SAID FIRST PUMP CYLINDER IS CAUSED TO MOVE FORWARDLY TOWARD THE OUTLET END THEREOF THE PISTON OF SAID SECOND PUMP CYLINDER IS CAUSED TO MOVE REARWARDLY, SIMULTANEOUSLY SAID VALVE MEANS HAS CLOSED THE OPENING BETWEEN SAID HOPPER AND SAID FIRST PUMP CYLINDER AND HAS OPENED THE OPENING BETWEEN SAID HOPPER AND SAID SECOND PUMP CYLINDER, AND SAID GATE VALVE MEANS HAS OPENED THE OUTLET END OF SAID FIRST PUMP CYLINDER AND HAS CLOSED THE OUTLET END OF SAID SECOND PUMP CYLINDER. 